Poly-1,2-azepines by the photopolymerization of phenyl azides. Precursors for conducting polymer films

Photochemistry of Azides: The Azide/Nitrene Interface

“…The precursor of 66a was assigned to isocarbazole 72a (Scheme 11.38 ). 214 LFP of perdeuterated azide 65a -d 9 at ambient temperature 214 demonstrated a pronounced kinetic isotope effect on the kinetics of carbazole formation on the ns time scale (k H /k D = 3.4 ± 0.2), which is consistent with the reaction being the isomerization of isocarbazole 72a into carbazole 66a by a 1,5 -hydrogen shift. In addition methanol and water were found to accelerate the disappearance of the transient absorption of 72a produced upon LFP of 65a in pentane.…”

“…20 reagents in synthetic organic chemistry, 229 in photoaffi nity labeling, 7,230 and for the covalent modifi cation of polymer surfaces. 9,10 The effects of the number and positions of fl uorine substituents on the ring expansion of phenylnitrene have been extensively investigated by the Platz group. 229,231 They concluded that fl uorine substitution at both ortho positions is required to inhibit the ring expansion effectively.…”

“…Therefore, the following scheme (Scheme 11.38 ) could economically describe the early results. 242 -245 Recently the mechanism of carbazole formation upon photolysis of ortho -biphenyl azide ( 65a ), its deutero -( 65a -d 9 ) and dichloro ( 65b ) derivatives was studied in detail using nanosecond laser fl ash photolysis, 154,214 time -resolved IR, 158,214 femtosecond transient absorption spectroscopy 154 -156 and computational chemistry. 154,156,214 LFP data obtained at room temperature 214 demonstrate that, in agreement with previous fl ash photolysis studies, 244b,245 carbazole 66a is mainly formed on the millisecond time scale in pentane.…”

“…214 In Freon -113 at ambient temperature, the lifetime of azirine 69a is 12 ± 2 ns, which is about 6 times shorter than that for isocarbazole 72a disappearance and carbazole 66a formation. The temperature dependence of the observed rate constants for the decay of azirines 69a and 69a -d 9 were studied and the activation parameters were found to be E RO = 5.7 ± 0.1 kcal/mol and A RO = 10 12.1 ± 0.1 s − 1 for 69a and E RO = 6.3 ± 0.1 kcal/mol and A RO = 10 12.6 ± 0.1 s − 1 for 69a -d 9 in satisfactory agreement with DFT calculations (Table 11.3 ).…”

Modification and bio‐testing of polyethylene films

“…Since then, many derivatives are the subject of extensive investigation because of their important biological and industrial applications as photoaffinity labeling agents [6][7], cross-linking reagents in photoresists [8], the formation of conducting polymers [9], and the light induced activation of polymer surfaces [10][11]. In the other hand, it is well known that sulfonamides are widely used for therapeutic and prophylatic purpose in humans and other animals and sometime as additives in animal feed [12].…”